High-bit-rate digital subscriber line

About: High-bit-rate digital subscriber line is a research topic. Over the lifetime, 516 publications have been published within this topic receiving 8537 citations. The topic is also known as: HDSL & high-bit-rate DSL.

Time-Shared Two-Wire Digital Subscriber Transmission System and Its Application to the Digital Telephone Set

Abstract: Adopting digital techniques in the local network area will enhance the possibility of extending digital operation capability to the subscriber's equipment. The problem is to convey digital signals at a bit rate of at least 64 kbits/s in both directions over existing two-wire subscriber loops. This paper describes a time-shared two-wire digital subscriber transmission system in which the directional separation of two signals (GO and RETURN) is accomplished by the time division bidirectional transmission method in burst-mode, and also reports results of investigations on the feasibility of an all digital telephone subscriber loop system.

Design Philosophy and Hardware Implementation for Digital Subscriber Loops

Abstract: This paper presents various requirements and configurations in the information network system (INS) NTT's version of the integrated services digital network (ISDN)- such as field trials, and technologies and equipment design of the digital subscriber loop using balanced wire pairs. The main aspects characterizing digital subscriber loops, are a customer access structure, a digital transmission system on existing subscriber loops, and customer interface. A configuration of two-wire digital subscriber loops with two customer access channels, which is adopted in the field trials, will be described. The time-shared two-wire digital transmission and power feeding methods on subscriber loops are discussed. The common mode rejection ratio (CMRR) is discussed in detail, since CMRR is one of the main factors which affects the transmission ability of balanced wire pairs. A proposed self-clocked four-wire customer interface utilizes time division multiplexing technique. The digital subscriber loop operates on a call-by-call basis for link establishment to avoid excessive power dissipations as well as to avoid impairments caused by crosstalk from other lines within a cable. Its design objectives and implementation are also discussed.

Adapted optimization criterion for FDM-based DMT-ADSL equalization

Abstract: The ANSI T1E1.4 Committee finalized the standardization of the asymmetric digital subscriber loop system and the usage of discrete multitone modulation as the ADSL line coding scheme. In order to separate the upstream channel from the downstream channel, the committee accepted two approaches as vendor options: echo cancellation and frequency division multiplexing. We illustrate the impact of the FDM approach on the equalization problem. The unsatisfactory performance of formerly known algorithms is described. A new, simple and near-optimal equalization optimization criterion that is an FDM-based DMT-ADSL is proposed.

Power control of digital subscriber line

Abstract: This invention relates to power control arrangements of digital subscriber lines. The invention controls parallel subscriber lines simultaneously in an organized way, based on the measurements of crosstalk conditions of the sub-scriber lines. Different crosstalk conditions are measured. The organized way to control the transmission power levels ensures that the crosstalk does not increase to an unacceptable level in each of the subscriber lines.

Subscriber's line switching control system

Abstract: SUBSCRIBER'S LINE SWITCHING CONTROL SYSTEM ABSTRACT OF THE DISCLOSURE In this invention, a call control information of a subscriber's line is compiled into a packet form, is transferred via a network of a digital switch board to a signal control device, and digital data is also trans-ferred via the network to a handler. Accordingly, a signal from a digital subscriber is efficiently pro-cessed, and an analog subscriber is also accommodated so that a call control in the same way as for the digital subscriber is made possible for the analog subscriber.